1. Field of the Invention
The present invention relates to a method for producing an ink jet recording head, in which a recording liquid generally called ink is discharged to fly in the form of a fine droplet from a fine opening, thereby depositing the fine droplet onto a recording surface to effect recording. More particularly, the invention relates to a method for producing an ink jet recording head in which the discharge opening surface of the ink jet recording head is surface treated.
2. Related Background Art
As shown in FIG. 1, generally, an ink jet recording head which is applied to the ink jet recording system is provided with fine ink discharge openings 4, liquid flow paths 6 and liquid discharge energy generating portions (not shown) arranged in the liquid flow paths. It is known that a peripheral portion of a discharge opening of the recording head is generally preferred to be ink-repellent from the view point of discharge stability. Further, the peripheral portion is exposed to an environment in which it is subject to wear or damage due to dust or foreign matters contained in the air or due to the contact with the recording media such as paper. For this reason, the peripheral portion is subjected to a treatment by which a material having ink repellence and some degree of abration resistance is applied.
As the method for imparting ink repellence to the discharge opening peripheral portion, besides the above mentioned method for applying an ink-repellent material onto the discharge opening peripheral portion, there can be included a method for forming a discharge opening of an ink-repellent material itself, a method of partially modifying the surface of the discharge opening forming member by implanting fluorine ions into a discharge opening peripheral portion or applying a fluorine plasma treatment thereto, and the like.
However, since, generally speaking, a coating material that is excellent in ink repellence does not always have a sufficient abration resistance, the above-described method for applying an ink-repellent material onto a discharge opening peripheral portion suffers from a problem that the peripheral portion may be damaged sometimes due to the cleaning step (wiping) for the discharge opening peripheral portion or the like, so that a discharge direction of ink may be deflected to deteriorate the printing quality level.
Also, as for the method for forming a discharge opening of an ink-repellent material itself, there is a fear that, since the ink-repellence is exhibited also in the liquid flow path, a good meniscus condition can not be maintained in the vicinity of the discharge opening, thus deteriorating the printing quality.
Furthermore, in the method of partially modifying the surface of the discharge opening forming member by implanting fluorine ions into a discharge opening peripheral portion or by applying a fluorine plasma treatment thereto, there is a problem that not only a large scale equipment is needed but also it is difficult to control to what degree the discharge opening peripheral portion of a discharge opening forming member is ink-repellent treated.
Thus, heretofore, there have been demands for a method for producing an ink jet recording head by which an ink jet recording head that is excellent in both ink repellence and abration resistance and has a high printing quality can be produced in low cost and at high yield.
In order to overcome the above-noted defects, an object of the present invention is to provide a method for producing an ink jet recording head which has good discharge stability and is excellent in productivity, and to provide an ink jet recording head produced by the method.
This and other objects are accomplished in accordance with the present invention by providing a method for producing an ink jet recording head comprising a discharge opening for discharging an ink, a discharge opening forming member for forming the discharge opening, a liquid flow path communicating with the discharge opening, and a liquid discharge energy generating portion arranged within the liquid flow path for generating an energy to be utilized for discharging the ink from the discharge opening, the method comprising dipping the discharge opening forming member into a liquid which has ink-repellence and permeates into the discharge opening forming member, whereby an ink-repellent treatment is effected on a peripheral portion of the discharge opening.
In the method for producing an ink jet recording head according to the present invention, since the ink-repellent treatment may be attained only by putting the discharge opening surface into a dipping tank, an equipment to be used for the ink-repellent treatment may be simplified, and it is possible to accurately carry out the desired treatment without complicated control of the treatment equipment. Accordingly, the productive yield is improved. Furthermore, in the ink jet recording head according to the present invention, since the ink-repellent substance permeates into the structural material (i.e., the discharge opening forming member) of the discharge opening surface, the hardness of the ink-repellent treated region of the discharge opening peripheral portion is substantially equal to that of the discharge opening forming member, whereby it is possible to keep a satisfactory abration resistance. Accordingly, a damage is hardly raised in the discharge opening peripheral portion and the ink discharge stability can be kept at a good level.